Small Engines (Lawn Mowers, etc.): John Deere 265, Kawaski engine problems, john deere 265, neighbor kids

Question
I'm having a problem 1994 JD 265.  It was running well with good power.  It began to act as though it had run out of gas when I was going up a medium incline, when it leveled out it ran good.  I went to refill gas tank and it was over half full.  I then thought fuel tank may have trash as my neighbor kids are notorious meddlers.  I drained the fuel tank, blew out the fuel line, replaced the fuel filter, removed the carb, bowl, cleaning it.  There was no indication of any trash or varnish in any of the above mentioned components.  I replaced the spark plug and replaced the dual stage air filters.  It started running fine again.  On a very hot day it began to come back with the same symptoms.  I let it sit for maybe 3 hours, restarted and it ran very well again.  Next time the same symptoms again. Not having time to go through what I had doen before, I took the mower to a very reliable repair shop.  Told them about all the symptoms and left it with them.  They purged the fuel tank, replaced the fuel filter.  The shop left me a message about the carb needed rebuilding.  As I was away for several days, when I called back the service manager said the tech decided it didn't need rebuilding and was able to resolve the issue.  Mower came home running good.  Last weekend it started acting up again.  It suddenly shuts down, it I disengage the PTO the the engine usually builds back up to speed.  Needing to finish, I slowed engine to about 1/2 throttle and mowed along very slowly, not problems other than not cutting very good.  Today, I went to finish to lawn, it is back doing the same thing shutting down, same symtoms several times today after stopping travel and disengaging PTO the engine died.  I would wait a few minutes, and do a regular start; fullthrottle/choke, engine starts runs good, start mowing maybe 15 feet starts cutting out again.  As the engine begins having problems the carb or gov begins to surge.  I was checking the fuel filter, a clear inline type, fuelfilter was only 2/3 full and as the engine surged I would see small bubbles near the bottom of the filter.  I hope you may have some idea what I need to be looking for to fix this thing.  Thanks  

Answer
 Hello James:

 If the Carburator isnt the Problem, then Check the Gas Tank Cap. If it isnt Venting Properly the Symptons you Described will Occur. Also the Valve Lash May be Too Close. I would think the Cap First. Also the Float May be Set too Low. The Float should be Level with the Bowl Seat when the Carburator is Turned so the Float is On Top. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John